I'm trying to use dotConnect for PostgreSQL to connect to EMC's GreenPlum implementation, which has some limitations.
For example it doesn't support the "RETURNING value" clause on an INSERT statement, which is commonly used to return the new primary key value on a automatically sequentially numbered record.

Calling the .AddObject method on an entity that has such a primary key defined gives me an error: "The RETURNING clause of the INSERT statement is not supported in this version of Greenplum Database."
Presumably dotConnect could generate SQL that didn't rely on the RETURNING clause to get .AddObjeect to work here.

2. Drag&drop the table on the model designer.
3. Right click on the Stored Procedures node in Store part of the model > Add > New Command Text:
Stored Procedure Name=insert_sp
SQL Script=insert into autoinc_table(mydata) values (:p0); select max(id) from autoinc_table;
Parameter's data type:
p0=varchar, direction=In
4. Right click on the class in CSDL > Stored Procedure Mapping, select Insert in the Commands list, and set:
a) Storage Procedure=insert_sp(p0 IN varchar)
b) Result Column Bindings:
Column=max, Property=Id:Int32
5. Execute the following code and make sure that id is returned from database: